Since their discovery, lasers have been used increasingly for commercial and military applications. High efficiency, high power output and simplicity of operation are desirable system characteristics for such lasers. Recently, attention has been focused upon the potential use of lasers for separation of isotopes, particularly isotopes of uranium. The important quality of the laser for achieving isotope separation is the spectral coincidence of the laser emission with an absorption line of a single isotope. A strong absorption band of uranium hexafluoride (UF.sub.6) is centered at a wavelength of approximately 16 micrometers (.mu.m).
Previous work with CO.sub.2 lasers on transitions which produce wavelengths of approximately 9.4 .mu.m and 10.6 .mu.m has been extensive. However, despite extensive research, the possibility of using stimulated emission at these wavelengths to cause stimulated 14 micron and 16 micron laser emissions from transitions to the 01.sup.1 0 CO.sub.2 vibrational level has only recently been suggested. Method and apparatus for achieving both 14 and 16 micron laser emission is described in detail in U.S. patent application Ser. No. 719,202, filed Aug. 30, 1976, entitled "GENERATION OF 14 MICRON AND 16 MICRON LASER RADIATION FROM A CO.sub.2 GAS LASER", U.S. Pat. No. 4,168,478, assigned to the assignee of the present invention incorporated herein by reference.
A technique for generating 16 micron laser radiation utilizing optical pumping is discussed by R. M. Osgood, Jr., in an article entitled: "Optically Pumped 16 Micron CO.sub.2 Laser," appearing in APPLIED PHYSICS LETTERS 28, 342, dated March, 1976.
Further disclosure of 14 micron and 16 micron CO.sub.2 laser radiation is described in U.S. Pat. Nos. 4,053,851 and 4,053,852, issued Oct. 11, 1977.